AT&T, Verizon had record 4th quarters thanks to the smartphone

The smartphone didn’t just drive holiday sales at the country’s biggest operators; it dominated those sales. This week at CES 2013, AT&T(s t) and Verizon Wireless(s vz)(s vod) reported record gross and net subscriber additions for the final three months of the year, all driven by big volumes of smartphones.

AT&T revealed at the show that it activated 10 million smartphones in the fourth quarter, mostly iPhones(s aapl) and Android(s goog) devices. That figure bests its previous record set in Q4 of 2011 of 9.4 million smartphones sold. According to the carrier, it averaged 110,000 smartphone sales a day during the three-month period.

Verizon hasn’t released its gross smartphone activations, but at a Citi(s c) conference held in conjunction with CES Monday, Verizon CEO Lowell McAdam said the carrier racked up 2.1 million net new subscribers in Q4, FierceWireless reported. Adam added that 85 percent of the device smartphones sold in the quarter were smartphones, and that 23 percent of its subscriber base now uses an LTE device, up from 16 percent in the third quarter.

That big jump in 4G subscribers has a lot to do with the new LTE-enabled iPhone 5, which went on sale in September. In fact, both carriers saw huge boosts in iPhone sales leading into the holidays. According to research group Kantar Worldpanel ComTech, in the 12 weeks leading up Nov. 25, iOS phones accounted for 71.8 percent of AT&T’s smartphone activations and 55 percent of Verizon’s — big increases over the same period in 2011 when the iPhone 4S was released.

The iPhone is also doing well at the single U.S. nationwide operator that doesn’t yet sell it. At the same Citi conference on Tuesday, T-Mobile USA CEO John Legere said it is connecting 100,000 iPhones a month and it currently hosts 1.9 million Apple smartphones on its GSM and HSPA+ networks, TMoNews reported. Though T-Mo doesn’t offer the device to its customers, it’s actively encouraging consumers to bring their unlocked iPhones to its network.

Of course, T-Mobile is only connecting the same number of iPhones a month that AT&T sells in a day, but that should change once T-Mo starts selling the device directly later this year.

Photo courtesy of Shutterstock user Stanislav Komogorov